This invention in general relates to a server-based navigation system and method of transmitting navigation data to a navigation unit and, more particularly, to a system and method that reduces the complexity of the unit and minimizes the data transmitted to the unit.
Devices that provide navigation guidance to a driver in a vehicle are well known. In conventional systems, a navigation unit is installed in the vehicle. The navigation unit typically has an interactive visual screen or buttons that allows a driver to enter a desired destination location. The navigation unit has memory or a CD drive that keeps map data and a processor that generates routes based on the map data and desired destination. Conventional navigation units having map data and map generation processors are expensive. They also require a user to update the map data and do not permit the unit to select a route based on other considerations such as current traffic patterns or delays.
There has been increasing interest in server-based navigation systems. A server-based navigation system typically downloads map information to a navigation unit by a wireless communication. The downloaded information contains the topology or other attribute information much like the original map information. The downloaded information can become quite large and may conflict with available bandwidth. Additionally, such systems still require excessive computations to be done by the navigation unit, increasing the complexity and cost of the navigation unit.
There is a need to reduce the computation complexity in a navigation unit. Reducing the computational complexity of the navigation unit reduces the cost of electronics required to perform vehicle navigation. Additionally, there is a need to decrease or minimize the amount of data transmitted to a navigation unit. Decreasing or minimizing the amount of data transmitted to the navigation unit allows the unit to respond quicker and reduces data usage and cost for the wireless communications.
It is, therefore, desirable to provide an improved navigation system and method to overcome or minimize most, if not all, of the preceding problems.